Shopper checkout is the process of identifying all of the products selected by a shopper, and then obtaining payment from the shopper for those products. Retail stores typically use two different techniques for shopper checkout. First, in the most common approach, a clerk employed by the store manually passes each product selected by the shopper past a universal product code (UPC) scanner, and the scanner reads the UPC code on each product. The UPC scanner is coupled to a computer, and the computer uses the scanned UPC code from each product to retrieve from a stored product list an identification of the product, and also the price of the product. The computer sums the individual prices of all products scanned in order to obtain a subtotal, and then adds any applicable taxes or other charges to the subtotal, thereby obtaining the total amount owed by the shopper. The clerk then obtains payment of that total amount from the shopper in order to complete the checkout process.
The other common approach is self-service checkout. During self-service checkout, it is the shopper rather than a store clerk who manually scans the UPC code on each product. A single clerk is typically present to monitor four or more self-service checkout stations, and to deal with any questions or problems encountered by shoppers operating the self-service checkout stations. The self-service approach is significantly less expensive for the store, because the store pays wages and benefits only for the single clerk who monitors several self-service checkout stations, instead of paying wages and benefits for several clerks who are each located at a respective different checkout station. On the other hand, the self-service approach has some drawbacks. For example, a shopper may inadvertently or intentionally fail to scan the UPC code on one or more products, such that the computer calculating the total amount due is not aware of those products and thus omits their prices from the total. As a result, the shopper ends up taking home one or more products that the shopper did not pay for.
While these traditional approaches have each been generally adequate for their intended purposes, they each have some drawbacks, and neither has been entirely satisfactory in all respects.